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Investigation of Optical Properties of Quantum Dots in Presence of Magnetic, Electrical Fields

Iranian researchers from University of Tabriz studied the effect of electrical and magnetic fields on optical properties of quantum dots in a theoretical research.

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New boron compounds for organic light-emitting diodes: Luminescent blue boron-containing nanographenes are highly promising materials for portable electronic devices

Major advances in the field of organic electronics are currently revolutionising previously silicon-dominated semiconductor technology. Customised organic molecules enable the production of lightweight, mechanically flexible electronic components that are perfectly adapted to individual applications. Chemists at the Goethe University have now developed a new class of organic luminescent materials through the targeted introduction of boron atoms into the molecular structures. The compounds described in the professional journal Angewandte Chemie (Applied Chemistry) feature an intensive blue fluorescence and are therefore of interest for use in organic light-emitting diodes (LED's).

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Customized organic molecules enable the production of lightweight, mechanically flexible electronic components that are perfectly adapted to individual applications are shown.

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Development of Gold Nanoparticles That Control Osteogenic Differentiation of Stem Cells

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Human mesenchymal stem cells (hMSCs) resulted from the following steps: each type of gold nanoparticles was added to hMSCs, and the treated cells were cultured for 3 weeks. The cells received either alkaline phosphatase (ALP) staining or alizarin red staining (ARS) of calcium phosphate deposits, both of which are osteogenic differentiation indicators. Control experiments with unmodified gold nanoparticles and untreated hMSCs were also carried out for comparison. In the upper images, ALP positive cells were stained purple while agglomerates of gold nanoparticles were detected as blue dots. In the lower images, spider-web-like red stains represent calcium phosphate deposits while bluish purple dots indicate agglomerates of gold nanoparticles. All scale bars are 500 μm.

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MIPT physicists develop ultrasensitive nanomechanical biosensor

It can analyze the chemical composition of substances and detect biological objects, such as viral disease markers, which appear when the immune system responds to incurable or hard-to-cure diseases, including HIV, hepatitis, herpes, and many others.

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This image shows the principle of the sensor.

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NIST's 'nano-raspberries' could bear fruit in fuel cells

Researchers at the National Institute of Standards and Technology (NIST) have developed a fast, simple process for making platinum 'nano-raspberries' -- microscopic clusters of nanoscale particles of the precious metal. The berry-like shape is significant because it has a high surface area, which is helpful in the design of catalysts. Even better news for industrial chemists: the researchers figured out when and why the berry clusters clump into larger bunches of 'nano-grapes.'

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Colorized micrographs of platinum nanoparticles made at NIST. The raspberry color suggests the particles' corrugated shape, which offers high surface area for catalyzing reactions in fuel cells. Individual particles are 3 to 4 nanometers (nm) in diameter but can clump into bunches of 100 nm or more under specific conditions discovered in a NIST study.

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Researchers Discover Electron Pairing without Superconductivity

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These images show differential conductance through the quantum dot as a function of the gate voltage that controls the number of electrons in the dot (x-axis) and the applied magnetic field (y-axis). Blue regions have low differential conductance and a constant number of electrons; green, yellow, and brown show higher differential conductance, indicating a change in the number of electrons in the dot. The top panel shows the measured differential conductance; the bottom panel shows the theoretical calculation (which has no disorder). Both experiment and theory show splitting of the electron pairs with increasing field and reentrant pairing at higher fields (the merging of pairs of boundaries into vertical boundaries).

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Cheap Method to Measure Medications in Contaminated Water

Iranian researchers from University of Tabriz, in association with a researcher from South Korea, designed a chemical fluorescent method for the measurement of medications in biological or medical samples by using quantum dots.

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Moving sector walls on the nano scale

Most magnetic materials have a structure that is somewhat more complicated than a commercially available domestic magnet: they not only have a north and south pole, but a variety of sectors, often only a few nanometres in size, in each of which the magnetic axis points in a different direction. These sectors are referred to as domains. Over the past few years, Manfred Fiebig, Professor for Multifunctional Ferroics at ETH Zurich, has been studying the walls between adjoining domains in certain materials. "The inner workings of a material and its domains are one area of interest," says Fiebig. "However, fascinating things also take place at the boundaries of these domains."

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Strontium manganite is a multiferroic, here present in a thin crystal layer. This magnified image shows the individual domains, which are only about 100 nanometres wide.

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Silica Nanoparticles Applied in Production of Drug Nanocarriers

Iranian researchers used new cheap materials through a simple method to synthesize biodegradable and biocompatible nanocarriers which control the rate and amount of drug release.

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World's smallest spirals could guard against identity theft

Take gold spirals about the size of a dime...and shrink them down about six million times. The result is the world's smallest continuous spirals: "nano-spirals" with unique optical properties that would be almost impossible to counterfeit if they were added to identity cards, currency and other important objects.

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This is a scanning electron microscope image of a single Archimedean nanospiral.